Structure constants and inner scales of temperature fluctuations were derived from ultrasonic anemometer-thermometer measurements taken at heights of 48 m and 80 m above the ground. They were shown to follow local Monin-Oboukhov similarity from very unstable to very stable atmospheric stratification. A direct empirical expression for the stability dependence of the nondimensional inner scale is given. A bichromatic scintillometer based on the wavelengths 0.63 μm and 10.6 μm was operated near the ground. Comparison between optically measured path averaged inner scales to those derived from point measurement of vertical velocity fluctuations yielded excellent agreement. The observed dispersion of refractivity fluctuations was used to separate structure constants of temperature and humidity. Surface fluxes obtained from parameterizations requiring only simple meteorological input data were applied to scale optically measured structure constants of temperature and inner scale. The parameterized fluxes were shown to be sufficiently accurate to be used in Monin-Oboukhov similarity based models.